Combination set-collar for well-strainers



A. THOMSON.

COMBINATION SET COLLAR FOR WELL STRAINERS.

APPLICATION FILED MAY 9, 1919.

1,323,205., Patented Nov. 25, 1919.

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im' am Fa IIIIII di L illlllllllIl-llllllllll ALEXANDER THOMSON, 0F SOURLAKE, TEXAS.

COMBINATION SET-COLLAR FOR WELL-STRAINERS.

Specification of Letters Patent.

Patented Nov. 25, 1919.

Application filed May 9, 1919. Serial No. 295,965.

To all whom t may concern.'

Be it known that I, ALEXANDER THOMSON,

a citizen of the United States, residing at-y Sourlake, in the county of Hardin and State of Texas, have invented certain new and useful Improvements in Combination Set- Collars for Well-Strainers, of which the following is a specification.

This invention relates to certain improvements in combination set collars for well vstrainers and has relation more particularly to a device of this general character especially designed and adapted for use in connection with the strainers for deep wells.

The object of my invention is to provide a novel and improved device of this character, combining a set collar the essential backpressure valve, and a seat integrally formed in the co-llar with which a washer pipe is adapted to coact when sinking the strainer in the water or oil ibearing sand, or when it is desired subsequently to cleanse the strainer.

The invention consists in the details of construction and in the combination and arrangement of the several parts of my improved device whereby certain important advantages are attained and the device rendered simpler, less expensive and otherwise more convenient and advantageous for use as will be best understood from a consideration of the following detailed description,

taken in connection with the accompanying drawings forming a part of this specication.

In the drawings Figure 1, is a view partly in elevation and partly in section illustrating a device constructed in accordance with my invention. Fig. 2 is a side view ofthe washer pipe seal, drawn to a larger scale. Figs. 3 and 4 likewise enlarged are respectively bottoni and side views of the back pressure valve.

As disclosed in the drawings l denotes an ordinary internally threaded coupling, the upper end portion thereof being for engagement with the well casing in the usual manner and assumed to be sunk to the proper depth. In engagement with the lower end of the coupling is shown a strainer, the illustration being to a large extent typical rather than illustrative of any particular strainer structure since they vary considerably; but as shown it comprises one or more joints of pipe 2 having a multiplicity of perforations 3, and around which is wrapped heavy brass or galvanized wire 4. To the lower end of the installed strainer the upper end of my set collar is shown in threaded engagement, and it comprises, in part, a cylindrical sleeve 5 interiorly thread- -ed at both ends. In threaded engagement with the`interior of the lower end of the sleeve 5 is an annular member 6, above it is loosely fitted for vertical movement an inverted cup shaped valve 7, the major diameter of the valve forms its guide in the chamber 8, and above it the diameter is materially reduced and terminates in a conically shaped end 9 adapted to seat against a correspondingly shaped portion 10 integrally formed within the sleeve 5. Four or more peripheral apertures l1, preferably square, extend radially at diametrically opposite portions of the reduced part of the valve shell.

Interposed between the annular member 6 and the base of the valve 7 is an expansible member l2 herein disclosed as a coil spring, and tending at all times to maintain thc valve normally closed against the seat 10 so that the ingress of sand or otherxforeign matter into the perforated pipe 2 is prevented. 13 denotes a washer pipe of a length to extend above the surface of the ground when the strainer is in applied position within a well, the lower end of said pipe has in threaded engagement therewith a wash plug 14, the cone shaped lower end of which engages a correspondingly shaped seat 15 formed in the sleeve 5. Surrounding the conical portion of the plug is a groove 16 that is filled with suitable packing-preferably lead, which coacts with the seat 15 to effect a tight closure when the plug is inserted in the sleeve. The vertical opening 17 through the plug equals the area of the washer pipe 13, and the bottom end is outwardly flared all around as shown at 181. A bridge 19 is integrally formed in the longitudinal axis of the sleeve 5 about midway thereof and slightly below the bottom end of the inserted plug 14, it has four or more vertical apertures 20, the combined areas of which. and the space 8 surrounding the valve 7, also vthe combined areas of the valve apertures 11 should respectively approximate that of the washer pipe 13.

Assuming that the well casing and stainer with my set collar attached has been sunk to the oil or water bearing stratum, the washer pipe 13 with plug 14 attached as shown in the drawings are lowered into the casing until the plug reaches the contracted seat 15,-water then being forced through the pipe 13 passes through plug 14 and thence through the apertures 20-in the. bridge, the force of the Water then displaces the valve 7 so the water under pressure flows into the chamber 8, thence through valve apertures l1 and out through the annular member 6, into the sand stratum.' The water jet thus produced bores its way into the sand so that the strainer may follow, and is continued until a predetermined depth has been reached. The bore Within the sand stratum may still be filled with heavy mud and this must be washed out with clear water, so the forcing of water through the washer pipe is continued to be discharged into the bottom o the well or bore, the preure of the water causes the same to travel upwardly exteriorly of the strainer and casing to the ground surface. When the well is thoroughly cleansed the washer pipe and plug are removed, leaving the well clear with the eX-' ception of being closed at the bottom with back pressure valve 7 which remains permanently in the well and serves to close the lower end of the strainer against the entrance of sand, the spring .12 being suciently strong to hold the valve in closed position.

cility with which it may be assembled and A operated. Having now set forth :the object and nature of my invention and a form of em bodiment of the same, and having described the construction, function, and mode of operation thereof, what l claim as new and desire to secure by Letters Patent, is-

In a'combination set collar orwell strainers, a cylindrical sleeve attached to the lower end ot the strainer, said sleeve being interiorly screw threaded at leach end and having acentrally located bridge portion with vertical apertures, a seat above the bridge adapted for engagement with a wash plug, a valve arranged beneath the bridge, and a seat therefor, and an annular apertured, member threaded within and near the lower-end of the sleeve supporting a coil spring, said coil spring adapted to resiliently support and maintain the valve normallyv against the seat. l

ln testimony whereof I ax my signature.

EXANDER 'Monson 

